Brain Irradiation and Tremelimumab in Metastatic Breast Cancer

A Simon 2-stage single-arm design (n=17) will be employed to evaluate for preliminary efficacy. A maximum of 17 subjects will be accrued to the efficacy arm. After the first 3 patients are enrolled in the efficacy arm, a 6 week enrollment hold will be conducted in order to ensure safety before additional patients are enrolled. An interim assessment will then occur after the first 9 subjects have enrolled, and the accrual to this arm will proceed only if a pre-specified futility threshold is met. Patients not requiring continuation of HER2 directed therapy, such as trastuzumab, will be enrolled in this arm.